Latching system for well swabbing tools

ABSTRACT

A latch system configured to permit one-way automatic passing of a swabbing tool. The latch system having a housing in communication with a well bore and a latch assembly housing a latch member with a latch. The latch is configured to selectively translate through an aperture in the housing. The latch assembly utilizes a biasing member to selectively control the location of the latch. The biasing member is sealingly separated from exposure to discharge fluids within the housing. While in an extended position, the latch allows the removal of the swabbing tool from the well bore but prevents the passing of the swabbing tool from a swab tube.

BACKGROUND

1. Field of the Invention

The present application relates generally to swabbing devices and, more particularly, to equipment for capturing a swabbing device.

2. Description of Related Art

Gas and oil well pumping or swabbing devices are used to remove oil and other substances from within an oil and gas well. A swabbing device is typically lowered within a well bore attached to a sandline and regulated by an operator. Once a desired depth is reached, the swabbing device is generally pulled to the surface. In doing so, the swabbing device typically expands within the well bore and proceeds to pull and/or remove the oil and other substances from the well between the swabbing device and the surface.

Operators of swabbing devices are responsible for safely removing the swabbing device from within the well bore. At times, an operator may get distracted and/or miss cues notifying him of the location of the swabbing device in relation to the surface. If such cues are missed, the swabbing device can reach the surface at too great a speed causing the swabbing device to break free from the sandline and fall back inside the well bore. At times a well becomes a “hot well” in which the downhole pressure becomes too great and pushes the swabbing device to the surface too fast causing the swabbing device to break free from the sandline after passing the well head, and therefore falling back into the well.

Large amounts of money are required to retrieve items that have fallen into well bores. The responsibility to retrieve such swabbing devices is generally dependent upon the location of the swabbing device when it fell into the well bore. Generally an operator is responsible for retrieving swabbing devices that have fallen into the well bore once the swabbing device has passed the swabbing tee during removal.

Because the sandline can break as a result of either operator error or neglect, or due to a “hot well”, a tool is needed that will permit the swabbing device to pass through the well head without interference and automatically prevent the device from falling back into the well.

Although great strides have been made, with respect to swabbing devices, considerable shortcomings remain.

DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the application are set forth in the appended claims. However, the application itself, as well as a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is an exemplary side view of a well with a latch system according to the present application;

FIG. 2 is a view partially in section and partially in elevation of the latch system as seen in FIG. 1;

FIG. 3 is a view partially in section and partially in elevation of the latch system as seen in FIG. 2, having an alternative embodiment of an actuating member;

FIG. 4 is a view partially in section and partially in elevation of the latch system as seen in FIG. 2, a swabbing tool being raised past a latch in the latch system of FIG. 1;

FIG. 5 is a view partially in section and partially in elevation of the latch system as seen in FIG. 4, the swabbing tool resting on the latch; and

FIG. 6 is a flow chart showing the method of operating the latch system of FIG. 1.

While the system and method of the present application is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the application to the particular embodiment disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the process of the present application as defined by the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Illustrative embodiments of the preferred embodiment are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present application, the devices, members, apparatuses, etc. described herein may be positioned in any desired orientation. Thus, the use of terms, such as above and below, to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein may be oriented in any desired direction.

Referring now to FIG. 1 in the drawings, a well utilizing a latch system according to the present application is illustrated. Well 10 is a combination of pipes and valves that extend into the earth into a subterranean formation to access natural minerals. A wellhead 14 is located atop the piping above the surface to regulate the flow of the well 10. The piping of well 10 defines a well bore 12 above and below the surface. Discharge fluids 15 are configured to pass within the interior of wellbore 12 and exit above or below wellhead 14.

Swabbing tools 16 are suspended from a sandline 18 and are lowered into and raised out of the interior of a well bore 12. The swabbing tool includes a mandrel body (not shown) and a number of swab cups (not shown) attached to the lower end of the mandrel. As the swabbing tool 16 is lowered in the well bore, the swab cups permit discharge fluid 15 within the well bore 12 to bypass the mandrel. Swab cups are free to move up and down a limited amount along the mandrel in a conventional manner. A sealing plate (not shown) is located below the swab cups adjacent a portion of the mandrel. When the swabbing tool 16 is raised in the well bore 12, the weight of discharge fluid 15 on the swab cups forces them down onto the sealing plate to prevent the passing of fluid 15. As the swabbing tool is then raised, the discharge fluid 15 above the swab cups is brought to the surface. The raising of the swabbing tool also generates a suction force within the well bore 12 below the swabbing tool. The suction draws discharge fluid 15 from the underground producing formation penetrated by the well 10 to enhance further production of discharge fluids 15.

A latch system 20 of the present application is also shown in communication with well 10. Latch system 10 is located above a swab tee 22 and wellhead 14. Latch system 20 is configured to couple to well 10 in a threaded relationship and to be in communication with the interior of well bore 12. Latch system 20 is directly in line with the interior of well bore 12, such that items may pass through latch system 20 to enter or leave well 10. In instances where a swabbing tool is used, a swab tube 24 is threadedly coupled to an upper portion of latch system 20 for housing and containing swabbing tool 16 when removed from well bore 12.

The present application will illustrate the uses of latch system 20 as it pertains to swabbing tool 16. It is understood that latch system 20 may be used with other systems in communication with well 10, such as plunger systems for example. Furthermore, uses of latch system 20 are not limited to use in the oil and gas industry. Other uses are considered to be within the scope of the present application. Use of the term discharge fluids 15 refers to any fluid and/or gas within well 10. Discharge fluids 15 also include any and all suspended particles intermixed within the fluids and/or gases of well 10.

Referring now also to FIGS. 2 and 3 in the drawings, latch system 20 is illustrated. Latch system 20 includes at least a housing 28 with a longitudinal bore 32 therethrough and a latch assembly 30 having a latch member configured to selectively extend into longitudinal bore 32. System 20 is configured to be a removeable fixture from well 10. As such, system 20 is configured to threadedly engage well 10 in a selectively releasable manner. Latch assembly 30 is configured to selectively permit the “one-way” passing of swabbing tool 16.

At an upper end 36 a and a lower end 36 b of housing 28 are threads 34 to engage similar threads formed on well 10 for the purpose of sealing and coupling system 20 to well 10. Although shown as having external threads, it is understood that housing 28 may rather have internal threads. Furthermore, it is understood that latch system 20 can optionally include the use of one or more adapters 26 (as seen in FIG. 1) to couple housing 28 to well 10. An advantage of using adapter 26 is the ability of system 20 to match various wells 10 having different thread measurements. Furthermore, adapters 26 permit the inside diameter of housing 28 to match that of well 10 where coupled together. This avoids the formation of protruding edges within the interior diameter from diameter variations that may work to cause tools within well 10 to become lodged or damaged.

Longitudinal bore 32 is in a coaxial alignment with the interior of well bore 12, thereby permitting fluid communication between bore 12 and bore 32. An aperture 38 is formed in the wall of housing 28 for use by latch assembly 30. An opening (not shown) is located opposite aperture 38 for use by a pressure gauge 40. Pressure gauge 40 has been omitted from view in FIGS. 2-5. Discharge fluids 15 are introduced into bore 32 and may pass through aperture 38 from bore 32.

Latch assembly 30 includes a latch body 42 and a cap 43. Body 42 extends radially from housing 28 and surrounds aperture 38. Cap 43 is threadedly coupled to the end of body 42 opposite housing 28, thereby defining a volume. A latch member 44 is slideably disposed within body 42. Latch member 44 includes at least a sealing member 46, a shaft 48, and a latch 50.

Latch assembly 30 is divided into two chambers. A latch chamber 60 exists in the volume of space within body 42 from a first surface 51 of sealing member 46 to aperture 38. A biasing chamber 62 exists in the volume of space from a second surface 58 to cap 43. Sealing member 46 acts as the divide between chambers 60, 62. Sealing member 46 includes a seal 54 disposed within a groove 56. Seal 54 is configured to maintain a fluid tight seal between body 42 and latch member 44. Seal 54 may be an elastomeric seal or a metallic 0-ring for example. Seals 54 maintain the fluid tight seal during translation of latch member 44.

It is understood that latch chamber 60 is exposed to discharge fluids 15. Furthermore, seals 54 are configured to prevent the penetration of discharge fluids 15 into biasing chamber 62. The relative volume of chambers 60 and 62 are variable due to the translation of latch member 44.

Latch 50 is partially disposed within body 42, partially and selectively extending through aperture 38 into longitudinal bore 32. Latch member 44 is configured to translate within body 42 in a relatively concentric alignment with body 42. Sealing member 46, shaft 48, and latch 50 are integrally formed together as a single member. Other embodiments may permit each to be separable. For example, other embodiments may permit latch 50 to be interchangeable from shaft 48 to adjust features of latch 50, such as size or depth within bore 32, to name a few.

Latch member 44 includes a latch shoulder 52 configured to contact the wall of housing 28 and act as a stopping mechanism to counter applied forces from a biasing member 53 in biasing chamber 62. It is understood that the shape and size of aperture 38 and/or shoulder 52 are of no particular size or shape and may vary depending on application. Shaft 48 extends between shoulder 52 and first surface 51 of sealing member 46. Sealing member 46 has an increased diameter as compared to shaft 48, although it is understood shaft 48 may have the same diameter as sealing member 48 and shoulder 52.

Latch assembly 30 includes biasing member 53 disposed within body 42 and cap 43 in chamber 62. Biasing member 53 is configured to apply a biasing force to extend latch member 44, and more particularly, latch 50 through aperture 38 and into bore 32. Biasing member 53 is configured to engage latch member 44, and therefore latch 50, and induce movement of latch member 44 within body 42. Biasing member 53 may be operated manually or automatically. During manual operation, biasing member 53 may be a spring (as seen in FIG. 2) for example. In alternative embodiments, biasing member 53 may be a hydraulic, pneumatic, and/or electronic device. Hydraulic, pneumatic, or electronic devices have the advantage of the capablility of being controlled via a remote location or operate through the use of sensors on a timed basis. An electronic, pneumatic, and/or hydraulic biasing member 63 is illustrated in FIG. 3.

Latch assembly 30 further includes an actuating member in communication with biasing member 53, 63 and latch member 44. The actuating member is configured to regulate biasing member 53, 63 and thereby induce controlled translation of latch member 44 within body 42. The actuating member is configured to access chamber 62 through an aperture 66 in cap 43. A variety of actuating members are contemplated.

As seen in FIG. 2, actuating member is biasing member 53. In manual operation, a lever 65 extends through aperture 66 relatively coaxial with body 42, however, a non-coaxial relationship is permitted in other embodiments with lever 65. Lever 65 may be coupled directly to biasing member 53. Lever 65 is configured to regulate biasing member 53 and therefore translate latch member 44 within body 42 as lever 65 is alternated between a first orientation and a second orientation. FIG. 2 illustrates lever 65 in a first orientation wherein latch 50 protrudes within bore 32 (see also FIG. 5). FIG. 4 illustrates lever 65 in a second orientation wherein latch 50 is retracted within chamber 60. Lever 65 may be a mechanical lever such as shown in FIG. 2, or may be an elbow latch for example. An operator may manually pull lever 65 away from cap 43 to compress biasing member 53 and retract latch 50.

As seen in FIG. 3, the actuating member used with latch assembly 30 is biasing member 63. In this embodiment, latch assembly 30 further includes a mechanical coupling 64 threadedly coupled to aperture 66. Coupling 64 is configured to have a fastener 68 configured to fasten any of the following: electrical connectors, pneumatic lines, or hydraulic lines, so as to be in communication with biasing member 63 and thereby induce translation of latch member 44. In this embodiment, an operator located on a truck to control the swabbing tool may selectively control biasing member 63. Control may be retained by the operator or may be surrendered to a second operator adjacent well 10 upon the desire of the operator.

Latch assembly 30 also includes cap 43. Cap 43 threadedly engages body 42. Cap 43 includes a seal 70 located in a groove 72 for sealing chamber 62. Cap 43 may be removed to permit the removal, repair, and/or replacement of latch member 44. Latch assembly 30 also includes one or more grease serts 74 to maintain and lubricate moving parts of latch assembly 30 within chambers 62 and 62. The application of grease in chamber 60 is to combat the affects of rust and corrosion from exposure to discharge fluids 15. Furthermore, the application of grease in chamber 60 may also aid in cleaning out any debris or suspended particles that may work to lodge between latch 50 and aperture 38, thereby restricting translation of latch member 44. The application of grease in chamber 62 is to provide lubrication and prevent premature wear of biasing member 53, 63. Although grease serts 74 are described as ports for the insertion of grease, it is understood that other fluids or products may be inserted through grease serts 74. For example, cleaning agents and/or water may be inserted. An advantage of serts 74 is the ability to prevent premature wear and replacement of latch assembly 30.

Referring back to FIG. 1, latch system 20 may optionally further include swab tee 22. Swab tee 22 is configured to be in communication with well bore 12 and to receive discharge fluid 15. Swab tee 22 acts to direct the flow of discharge fluid to one or more tanks or containers for the storage and/or separation of discharge fluid 15. Wherein latch system 20 includes swab tee 22, in one embodiment swab tee 22 and latch system 20 are integrally coupled along lower end 36 b, such that housing 28 and swab tee 22 are one continuous single member. In such an embodiment, adapters 26 are not required between swab tee 22 and housing 28.

Latch system 20 may optionally further include swab tube 24. Swab tube 24 is configured to be in communication with housing 28 and longitudinal bore 32. Swab tube 24 is coupled to the upper end 36 a and serves to contain swabbing tool 16. Upon removal of swabbing tool 16 from well 10, swabbing tool 16 is configured to pass latch system 20 and enter swab tube 24. Wherein latch system 20 includes swab tube 24, swab tube is integrally coupled along upper end 36 a, such that housing 28 and swab tube 24 are one continuous single member. In such an embodiment, adapters 26 are not required between swab tube 24 and housing 28. It is understood that latch system 20 may optionally include both swab tee 22 and swab tube 24 in other embodiments.

Referring now also to FIGS. 4-6 in the drawings, latch system 20 is illustrated during operation of swabbing tool 16. Latch 50 is shaped to permit the one-way passing of swabbing tool 16 while in an extended position. Latch 50 has a surface 47 along an upper portion that is relatively perpendicular to bore 32. Latch 50 has a contoured surface 49 along a front and lower portion of the latch. While in an extended position, swabbing tool is denied the ability to pass when entering from upper end 36 a. Swabbing tool contacts surface 47 which acts as a lip to stop the swabbing tool 16. While in an extended position, swabbing tool is permitted to pass when entering housing 28 from lower end 36 b. In this direction, swabbing tool 16 contacts surface 49. Surface 49 is configured and shaped to receive an upward force from swabbing tool 16 and transmit that force against biasing member 53, 63 so as to overpower biasing member 53, 63, thereby retracting latch 50.

In operation, latch system 20 is coupled 76 to well 10. Swab tube 24 is coupled to latch system 20 if not ingetrally coupled. Swabbing tool 16 is located within swab tube 24 in a coaxial alignment and in communication with housing 28. Latch 50 is operated 78 to be in a retracted position, so as to permit the passing of swabbing tool 16 through latch system 20. Operating latch 50 refers to either retracting or extending latch 50 with respect to housing 28. When retracted, latch 50 permits swabbing tool to pass through housing 28. When initially lowering swabbing tool 16, latch 50 is operated so as to be in a retracted position. After swabbing tool 16 has passed through housing 28, latch 50 is operated so as to be in an extended position within bore 32.

While extended, latch 50 is configured to avoid interference with sandline 18. This permits swabbing tool 16 to be located 80 and moved within well bore 12. During removal of swabbing tool 16 from well bore 12, latch 50 is left in an extended position within bore 32. Swabbing tool 16 contacts surface 49 with sufficient force to overcome biasing member 53, 63 and automatically retract latch 50 within body 42. FIG. 4 illustrates the position of latch 50 when swabbing tool 16 is raised. As seen in FIG. 4, biasing member 53 is overcome and swabbing tool 16 is permitted to pass. After passing, biasing member automatically extends latch 50 through aperture 38 and into bore 32. In the event that swabbing tool 16 breaks free from sandline 18 and falls back through swab tube 24, swabbing tool 16 is stopped by contact with surface 47. FIG. 5 illustrates swabbing tool 16 resting on upper surface 47 of latch 50.

An operator may service 82 latch system at any time, whether in use or not. To service latch system 20, an operator may remove cap 43 and withdraw latch member 44 and/or biasing member 53, 63. Furthermore, servicing 82 may include applying grease or other substances through grease serts 74. An additional step during the operation of swabbing well 10 may include transferring control of latch system 20 from manual to remote, or remote to manual. It is understood that the operation of swabbing tool 16 in relation to latch 50 is similar regardless of whether biasing member 53 or 63 is used.

The current application has many advantages over the prior art including the following: (1) one-way passing of a swabbing tool; (2) ability to lower and raise the swabbing tool while the latch is extended; (3) dual chambered latch assembly; (4) ability to service the latch assembly during operation of a swabbing device; and (5) ability to clean, maintain, and service the latching member and biasing member without removing them from the body and cap.

The particular embodiments disclosed above are illustrative only, as the application may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. It is therefore evident that the particular embodiments disclosed above may be altered or modified, and all such variations are considered within the scope and spirit of the application. Accordingly, the protection sought herein is as set forth in the description. It is apparent that an application with significant advantages has been described and illustrated. Although the present application is shown in a limited number of forms, it is not limited to just these forms, but is amenable to various changes and modifications without departing from the spirit thereof. 

What is claimed is:
 1. A latch system for a well head, comprising: a housing configured to couple to the well head, the housing in communication with a well bore to permit the passing of discharge fluids, the housing having an aperture; and a latch assembly having a body coupled to the housing, the latch assembly comprising: a latch configured to selectively engage the aperture and extend internally to the housing; and a biasing member configured to engage the latch and permit selective translation of the latch within the latch body; wherein the biasing member is sealingly separated from exposure to discharge fluids.
 2. The latch system of claim 1, wherein the latch of the latch assembly is manually operated.
 3. The latch system of claim 1, wherein the biasing member is a spring.
 4. The latch system of claim 1, wherein the translation of the latch is controlled by remote operation.
 5. The latch system of claim 1, wherein the biasing member is a hydraulic device.
 6. The latch system of claim 1, wherein the biasing member is a motorized device.
 7. The latch system of claim 1, further comprising: a lever in communication with the latch and being configured to translate the latch within the body as the lever is alternated between a first orientation and a second orientation.
 8. The latch system of claim 1, further comprising: an optional adapter to threadedly couple the housing to the well bore.
 9. The latch system of claim 1, further comprising: a grease sert configured to provide lubrication to at least one of the latch and the biasing member.
 10. The latch system of claim 1, wherein the latch is configured to prevent the passing of a swabbing tool through the well bore after the swabbing tool has cleared the well head.
 11. The latch system of claim 1, further comprising: a swab tee in communication with the well bore and being configured to receive the discharge fluid from the well bore.
 12. The latch system of claim 1, further comprising: a swab tube coupled to an upper end of the housing, the swab tube in communication with a swabbing tool, the swab tube configured to contain the swabbing tool outside of the well.
 13. A method of swabbing a well having a wellhead and a well bore, comprising: coupling a latch system to the well, the latch system having a latch body and a housing in communication with the well bore; locating a swabbing tool within the interior of the well bore; and operating a latch to extend internally within the housing, the latch being biased by a biasing member sealingly separated from discharge fluids within the well bore; wherein the latch is configured to automatically permit the passing of the swabbing tool in a single direction while extending internally within the housing.
 14. The method of claim 13, wherein the latch permits the free motion of the swabbing tool within the well bore while in an extended position within the interior of the housing.
 15. The method of claim 13, wherein the latch is manually operated.
 16. The method of claim 13, wherein the latch is operated from a remote location.
 17. The method of claim 13, further comprising: transferring control of the latch system between a manual operation and a remote operation.
 18. The method of claim 13, wherein at least one adapter is used to couple the latch system to the wellhead.
 19. The method of claims 13, wherein the housing is integrally coupled to a swab tee configured to receive the discharge fluids.
 20. The method of claim 13, further comprising: retracting the latch to permit the lowering of the swabbing tool, such that the swabbing tool enters the wellhead. 